Portable battery charger



FIG. 1 is a perspective view of a portable battery charger showing the new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is bottom plan view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a front elevation view thereof;

FIG. 7 is a rear elevation view thereof; and,

FIG. 8 is a perspective view thereof illustrating the charger with its charging plug exposed.

The broken lines shown in FIG. 8 are included for the purpose of illustrating portions of the portable battery charger that form no part of the claimed design. 

CLAIM The ornamental design for a portable battery charger, as shown and described. 